What is CVE-2026-20126?
A vulnerability in Cisco Catalyst SD-WAN Manager could allow an authenticated, local attacker with low privileges to gain root privileges on the underlying operating system. This vulnerability is due to an insufficient user authentication mechanism in the REST API. An attacker could exploit this vulnerability by sending a request to the REST API of the affected system. A successful exploit could allow the attacker to gain root privileges on the underlying operating system.
The record classifies CVE-2026-20126 under weakness class CWE-648. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity, availability. 2 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 245 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 8.8 — HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS (FIRST)
- 0.3% probability of exploitation in the next 30 days, higher than 21.4% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 7.3/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-02-25, last modified 2026-03-20
Is CVE-2026-20126 being exploited?
Weaponised exploit code for CVE-2026-20126 is publicly available. 1 public proof-of-concept repository is tracked for this identifier. It currently carries a trending score of 18 in the Threadlinqs vulnerability feed.
- trickest/cve (trickest)
Affected products and versions
- Cisco: Catalyst Sd-wan Manager, Catalyst Sd-wan Manager 20.12.6
How to fix CVE-2026-20126
The record marks a vendor fix as available for CVE-2026-20126. Vendor advisory: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-authbp-qwCX8D4v. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.
Threat activity tracking CVE-2026-20126
1 tracked threat in the Threadlinqs corpus references CVE-2026-20126, either in the campaign’s CVE list or as an indicator on the campaign record.
Sources
Enriched from CVE.org, FIRST EPSS, public proof-of-concept repositories. Last verified by Threadlinqs on .